/*
 * Open Source Physics software is free software as described near the bottom of this code file.
 *
 * For additional information and documentation on Open Source Physics please see: 
 * <http://www.opensourcephysics.org/>
 */

package org.opensourcephysics.controls;
import javax.swing.*;

import java.awt.*;
import java.awt.event.*;

/**
 * A dialog for verifying passwords with a single public static method verify().
 *
 * @author Douglas Brown
 * @version 1.0
 */
public class Password extends JDialog {
	
	// static fields
	private static Password dialog;
  	
	// instance fields
	private JLabel messageLabel;
	private JPasswordField passwordField;
	private String password;
	private boolean pass;

	/**
	 * Shows the dialog and verifies user entry of the password.
	 * 
	 * @param password the password
	 * @param filename the name of the password-protected file (may be null).
	 * @return true if password is null, "", or correctly verified
	 */
	public static boolean verify(String password, String fileName) {
		if (password == null || password.equals("")) return true; //$NON-NLS-1$
		if (dialog == null) dialog = new Password();
		dialog.password = password;
		if (fileName == null || fileName.equals(""))  //$NON-NLS-1$
			dialog.messageLabel.setText(
						ControlsRes.getString("Password.Message.Short")); //$NON-NLS-1$
		else 
			dialog.messageLabel.setText(
						ControlsRes.getString("Password.Message.File") //$NON-NLS-1$
						+ "\"" + XML.getName(fileName) + "\"."); //$NON-NLS-1$ //$NON-NLS-2$
		dialog.pack();
		// center on screen
		Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
		int x = (dim.width - dialog.getBounds().width) / 2;
		int y = (dim.height - dialog.getBounds().height) / 2;
		dialog.setLocation(x, y);
		dialog.pass = false;
		dialog.passwordField.setText(""); //$NON-NLS-1$
		dialog.setVisible(true);
		return dialog.pass;
	}

	/**
	 * Private constructor.
	 */
	private Password() {
		super((Frame)null, true); // modal with no owner
		setTitle(ControlsRes.getString("Password.Title")); //$NON-NLS-1$
		createGUI();
		setResizable(false);
		passwordField.requestFocusInWindow();
	}

	/**
	 * Creates the visible components.
	 */
	private void createGUI() {
		// create input panel
		GridBagLayout gridbag = new GridBagLayout();
		JPanel inputPanel = new JPanel(gridbag);
		// create components
		messageLabel = new JLabel();
		JLabel fieldLabel = new JLabel(
						ControlsRes.getString("Password.Label")); //$NON-NLS-1$
		passwordField = new JPasswordField(20);
		passwordField.setToolTipText(
						ControlsRes.getString("Password.Tooltip")); //$NON-NLS-1$
		passwordField.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				String input = String.copyValueOf(passwordField.getPassword());
				if (password != null && !input.equals(password)) {
					Toolkit.getDefaultToolkit().beep();
					passwordField.setText(""); //$NON-NLS-1$
				}
				else {
					pass = true;
					setVisible(false);
				}
			}
		});
		passwordField.addKeyListener(new KeyAdapter() {
      public void keyPressed(KeyEvent e) {
        if(e.getKeyCode()==KeyEvent.VK_ESCAPE) {
  				passwordField.requestFocusInWindow();
  				setVisible(false);
        }
      }
    });
		// create buttons
		JButton cancelButton = new JButton(
						ControlsRes.getString("Password.Button.Cancel")); //$NON-NLS-1$
		cancelButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				passwordField.requestFocusInWindow();
				setVisible(false);
			}
		});
		JButton okButton = new JButton(
						ControlsRes.getString("Password.Button.Enter")); //$NON-NLS-1$
		okButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				String input = String.copyValueOf(passwordField.getPassword());
				if (password != null && !input.equals(password)) {
					Toolkit.getDefaultToolkit().beep();
					passwordField.setText(""); //$NON-NLS-1$
					passwordField.requestFocusInWindow();
				}
				else {
					pass = true;
					setVisible(false);
				}
			}
		});
		// input panel in center
		Container contentPane = this.getContentPane();
		contentPane.add(inputPanel, BorderLayout.CENTER);
		GridBagConstraints c = new GridBagConstraints();
		// add message to input panel
		c.insets = new Insets(20, 15, 10, 15);
		gridbag.setConstraints(messageLabel, c);
		inputPanel.add(messageLabel);
		// add label and password field to input panel
		JPanel entry = new JPanel();
		entry.add(fieldLabel);
		entry.add(passwordField);
		c.gridy = 1;
		c.insets = new Insets(0, 10, 10, 10);
		gridbag.setConstraints(entry, c);
		inputPanel.add(entry);
		// button pane at bottom
		JPanel buttonPane = new JPanel();
		contentPane.add(buttonPane, BorderLayout.SOUTH);
		buttonPane.setLayout(new BoxLayout(buttonPane, BoxLayout.X_AXIS));
		buttonPane.setBorder(BorderFactory.createEmptyBorder(0, 10, 4, 4));
		buttonPane.add(Box.createHorizontalGlue());
		buttonPane.add(okButton);
		buttonPane.add(Box.createRigidArea(new Dimension(4, 0)));
		buttonPane.add(cancelButton);
	}
}

/*
 * Open Source Physics software is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License (GPL) as
 * published by the Free Software Foundation; either version 2 of the License,
 * or(at your option) any later version.
 * 
 * Code that uses any portion of the code in the org.opensourcephysics package
 * or any subpackage (subdirectory) of this package must must also be be
 * released under the GNU GPL license.
 * 
 * This software is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU General Public License along with
 * this; if not, write to the Free Software Foundation, Inc., 59 Temple Place,
 * Suite 330, Boston MA 02111-1307 USA or view the license online at
 * http://www.gnu.org/copyleft/gpl.html
 * 
 * Copyright (c) 2007 The Open Source Physics project
 * http://www.opensourcephysics.org
 */
